No upcp or logwatch emails

I have set up cronjobs for the root account by specifying the jobs in a text file and then running:
crontab file.txt

After that I stopped getting mails from Logwatch and upcp so I guess my cron setting deleted some old default cron settings made by CPanel.

Can someone please bring light on this? Does CPanel set up cronjobs by default for the root user? Will I be fine just enabling logwatch and upcp to execute daily? Are there other jobs set up by CPanel which I am likely to have deleted?